Treatment in gas distribution systems



April 6, 1943. J. R. SKEEN TREATMENT IN GAS DISTRIBUTION SYSTEM Filed001.. 24', 1938 Patented Apr. 6, 1943 UNITED s'r r s- PATENT- OFFICETREATMENT IN GAB DISTRIBUTION SYSTEMS 5.1... n. Skeen, Philadelphia, Pa,assignor to The United Gas Improvement Company, a corpora- ApplicationOctober 24, 1938, Serial No. 236,822

tion of Pennsylvania 8 Claims.

This invention pertains generally to the treatment of the interiors ofgas mains or other gas enclosures for the purpose of sealing joints orlaying dust, or both..

Systems for the distribution of gas include conduits or mains which areusually laid underground, and which comprise sections of pipe joinedtogether either by means of welding, by

means of packed joints, by means of screw joints or otherwise.

The welded joint is a more recent development and is used chiefly tojoin pipe sections of steel or iron, other than cast iron.

Older mains are usually made up of cast iron pipe sections joined bymeans of bell and spigot or other similar joints. These joints areusually packed withhemp, jute, flax or other cellulosic material whichin turn is backed up with lead or some of the oils) are condensed out.There is then no longer sufllclent water vapor in th gas when expandedto the low pressure to keep the fibrous packing in the packed joints inthe low pressure mains moist. On the contrary, the gas is so dry that itrapidly draws out any absorbed moisture in the packing at a ratedepending somewhat upon the accumulation of tan-resin and gum. However,the packing eventually dries out since the accumulation of tar, resinand gum is rarely capable of sealing moisture in the'flbers. It followsthat when the packing dries out serious leaks occur.

In other words, as long as the main is used fordistributing ordinarymanufactured gas, and assuming that the untarred type of packing wasoriginally installed, very little trouble with joint leakage isexperienced. However, when the cement or other material in a well knownmanner. V

The lead or cement seal is tight and .efiective in preventing gasleakage when first applied but soon loses this quality dueto expansionand contraction of the main with change in temperature or for otherreasons. eflectiveness of the joint in preventing gas leakage dependsentirely upon the packing.

Generally speaking,,there are two types of cellulosic packing or yarnwhich have been used in,

joints of gas mains or other gas enclosures.

At the time of their insertion in the joint, packing materials may beclassified as absorbent and non-absorbent in that the' capacity of theformer to absorb water has not been impaired by special treatment,whereas such capacity of the latter has been removed such as bytreatment with tar.

These widely diflerent types of packing may be referred to as untarred"and "tarred respectively, and have widely difierent characteristics.

in service. For instance, the untarred type of packing is capable ofabsorbing water which in turn swells the packing. This capacitycontinues until partially or wholly impaired by the accumulation of tar,resin and gum formed from constituents in the gas, the tar, resin andgum coating the packing. When this occurs the capacity of the packing totake up and give off moisture with change in gas humidity isconsiderably reduced and the packing takes on the charlocaldistribution, most of the water vapor (and When this happens the'service is changed over to a manufactured gas of lower moisture content,or over to natural gas which is characterized by a very low moisturecontent, or over to mixtures,'the packing dries out and shrinkssufliciently to cause the joint to become leaky.

While the use of the tarred type ofpacking avoids the absorption ofwater in the first instance, and consequent drying and shrinkingshouldthe moisture content of the gas be lowered,

nevertheless, the tarred type of packing has not been wholly successful.This is thought to be due in part to shrinkage in volume or crackingofthe tar due to drying or polymerization, and also in part to thenecessity of swelling a packing in a joint to cause the packing toconform more exactly to the contour of the joint and to reduce voidsbetween the fibers. I Soap is sometimes applied to the untarred type ofpacking. Such treatment, however, does not prevent drying and shrinking.

Referring now to the problem of dust, it is to be noted that over aperiod of years the water condensed from wet gas together with otherconstituents of the gas such as carbon dioxide, hydrogen sulfide,hydrocyanic acid, naphthalene, and

so forth, have in many instances, caused extensive corrosion of theinterior walls of the mains.

The products of corrosion have accumulated on the walls of the mainsand, in many instances, large quantities have become disconnected andhave collected along the bottom.

Due to the presence of relatively large quantities of moisture, largelyresponsible for the cor= 1 rosion in the first instance, the products ofcorrosion were maintained in a wet condition and did not tend to termdust in any appreciable quantity.

Therefore, until high pressure distribution came into practice, andwhile the use of natural gas or natural gas mixtures was lesswidespread, very little dimculty was experienced with the Monophenylether of ethy one g formation of dust in mains from the products ofcorrosion.

Inother words, as long as a main is used for distributing ordinary wetmanuiactured gas very little trouble with dustresulting from corrosionis experienced. However, when the service is changed over to amanufactured gas of low moisture content, or over to natural gas ornatural gas mixtures which are characterized by very low moisturecontent, the moisture on and in the corrosion products dries out andsuch products become a serious source of dust.

The presence of considerable quantities oi dust in the gas flowingthrough the mains of a distri= bution system is very undesirable becausedust tends to clog up customer service connections,

interferes with the proper operation of meters, and tends to clog upburners and pilot outlets.

Under extreme conditions corrosion maybe so severe as to form. a seriousobstruction in the main itself by reducing its eflective cross-sectionalarea such as by the accumulation of dust in piles in the main.

Since the corrosion products comprise not only ordinary iron rust butalso a variety of other compounds resulting from the action of hydrogensulfide, hydrocyanicacid, naphthalene, and other corrosive substances,the problem of wetting down the dust, of wetting the main wall,

and of thoroughly spreading a dust laying liquid becomes a major factor.

While the water miscible high boiling alcohols are generally suitablefor the purpose of laying dust as described and claimed in copendingapplication Serial Number 167,316, filed October 4, 1937 by Duncan 3.Williams, which has matured into Patent 2,167,140, July 25, 1939, onlythree 01 the substances specifically set forth in said application arecapable of swelling cellulosic fibre packing to the same extent aswater. With dry jute the volume increase caused by the swelling I havediscovered two additional substances namely, mono-methyl ether ofethylene glycol and mono-methyl ether or diethylene glycol which arecapable of swelling .cellulosic fibre packing sumciently to preventjoint leakage as described and claimed in my copending applicationSerial Number 128,555 filed March 1, 1937, wghich has matured intoPatent 2,141,959, Dec. 2'1,v 1 38.

The percentage swelling o1 dryjute by a num ber of liquids is set forthin Tables 1 to 3:

TABLE 1 Swelling Swelling Per cent Triethylone 1m Mono-ethyl et oftriethylene qly Mono-methyl my] other of silly ene glycol- Mono-ethylether of diethylene glycoL Mono-ethyl ether of ethylene glycol.

TABLE 3 Substance Swelling I I. Mixed tar bases P" n Disinte tesDisinteg tes Disintegrates A number of liquids suitable for dust layingare set forth in Tzi-ie 4.

TABLE 4 Non-cyclic high boiling aliphatic alcohols:

It should be noted that Table 4 includes not only the liquids of Table 1which alone are suitable ior swelling joint packing, but also liquids ofTable 2 as well as others which in themselves are not suitable forswelling joint packing.

All of the substances listed in Table 1 are of relatively low vaporpressure compared to water and are relatively inert in the presence ofthe gas.

Each of them except glycerine is rapidly absorbed by uncoatecl packing.Highly concentrated glycerine has a viscosity which is somewhat too highfor rapid absorption by the packing. This quality, however, may begreatly improved as will hereinafter appear.

Likewise, all of the substances of Table 4 are of low vapor pressurecompared to water and are relatively inert in the presence of the gas.

In many distribution systems tar, resin, gum, and dust have beendeposited upon the packing and operate to exclude the substances listedin Table 1 from contact with the packing. In the case of packing whichwas originally tarred, these substances are, of course, also excludedfrom contact with the packing. The substances of Table 1 are ratherdeficient as softening or solubilizing agents for tar, resin and gum.

The tar, resin, and gum likewise prevent the. materials of Table 4 fromreaching and wetting active sources and potential sources or dust, thesematerials being likewise for the mostv part deflcient as softening orsolubilizing agents.

A feature of this invention is to provide an improved leak proofingcomposition for swelling cellulosic packing in Joints of gasdistribution [5 systems which possesses sumcient solvent power withrespect to tar, resin and gum to cause the swelling constituents of thecomposition to be absorbed by the packing with suillcient rapidity for.

Another feature of the invention is to provide a joint sealing and/ordust laying composition having improved wetting qualities not only fortar, resin and gum, but also for cellulosic fibre, for corrosionproducts, and for the metal of the main walls.

Another feature of the invention is to provide a.

new article of manufacture and a process for making the same.

Other features of the invention will become more apparent to personsskilled in the art as the specification proceeds.

Generally speaking, the improvement in leak proofing compositionscomprises two or more mutually miscible liquids, one of which isespecially adapted to be absorbed by the packing and to swell thepacking to at least substantially the same extent as water; and theother of which is especiallyadapted (a) to soften o'r dissolve tar,resin and/or gum which may cover the packing, and (b) to assist thespreading and climbing of the swelling agent in the joint packing. In.the

event that these two or more liquids are not, in themselves mutuallymiscible in the quantities employed, a miscibility agent may be added.Such agent may comprise a liquid solvent in which the two or moreliquids employedare soluble.

Examples of the first mentioned liquid of the leak proofing compositioncomprise any one or more of the substances listed in Table '1, suchsubstances being mutually miscible with each other.

Examples of the second mentioned liquid of the leak proofing compositioncomprise the following groupof substances and mixtures of the same, suchas, with each other or with other tar penetrating agents:

Quinoline, isoquinoline, and their mixtures. Crude coal tar quinoline isan example of a mixture containing other materials. While the boilingrange may be from 95 C. to 350 C., a narglycol (phenyl cellosolve) isdescribed and claimed. I l

Reference is also made to my copending application Serial Number2'18,499, filed June 10, 1939', in which the employment of main treatingliquid mixtures containing a non-cyclic high boiling aliphatic alcoholand a ketone is described and claimeda l Referring now to dust layingcompositions, generally stated, the improvement comprises two or moremutually miscible liquids one of which is adapted to wet, hold and/orbind dust particles and to coat dust sources; and the other of which isadapted (a) to soften or dissolve tar, resin and/or gum which may coverdust sources or form incrustations with dust deposits and (b) to assistthe spreading and climbing of the dust lay- Examples of-the firstmentioned liquid of the dust laying composition comprise any one or moreof the substances listed in Table 4.

Examples of the second mentioned liquid of the dust laying compositionare' the quinolines and their mixtures listed above in connection withthe leak proofing composition.

Examples of miscibility agents suitable for incorporation in dust layingcompositions to insure a single liquid phase are:

Methyl carbitol Butyl carbitol Phenyl cellosolve Acetone Diacetonealcohol Mesityl oxide Any desired quantity of my tar, resin and/or gumsoftening and/or solubilizing and wetting agent (referred to hereinafterand in the claims forconvenience as tar penetrating agent) may be addedto the fiber swelling and/or dust laying liquid. I find, for example,that for ordinary purposes from 5% to 20% is sumcient, but in extremecases such as when the packing is of the tarred type or large quantitiesof tar, resin and/or gum have deposited from the gas, I find that muchlarger quantities might be employed.

rower out such as from 200 C.'to 300 C. is preferred. Any other suitablerange might be used. A cuthaving an initial boiling point of 200 C. or

, above is very effective.

Examples of miscibility agents suitable for incorporation in leakproofing compositions to insure a single liquid phase are:

Methyl carbitol (mono-methyl ether of diethylene glycol) Butyl carbitol(mono-butyl ether of diethylene glycol) Phenyl cellosolve (mono-phenylether of ethylene glycol) Acetone.

phaticalcohol and mono-phenyl ether of ethylene 7 for example, up to say70% or more.

It will, of course, be seen that a more drastic treatment might befollowed by a less drastic treatment, if desired. v

The presence of my tar penetrating agent greatly increases thedistribution of the treating liquid and its penetration through tar,resin, gum and dust incrustations and, therefore, not only greatlydecreases the time of treatment, but also greatly increases thethoroughness and effectiveness of the treatment when tar, resin, gumand/or dust incrustations are present.

-I find that my tar penetratingagents do not interfere with thefunctions of the other ingredients of the composition, and greatlyenhance the spreading and climbing of the same.

Furthermore, quinoline has the capacity of making cellulosic fibresexceptionally stiff which is highly desirable in the prevention of jointleakage.

Because solutions containing phenols have a slight corrosive action uponiron, I find it preferable when these substances are present to add asuitable corrosion inhibitor, such as triethanolamine, of which amountsfrom 0.5 to 1.5% are found to be particularly suitable. Such additionalso might be made in other instances, if desired. 1

The use of the phenols. as tar penetrating agents in joint sealing anddust laying compositions is more particularly described and claimed inmycopending application Serial Number 128,556, filed March 1, 1937.

Examples of liquid mixtures for both leak proofing and dust laying areas follows:

Example 1 Percent Dlethylene glyc 65 Glycol-inn 15 Quinoline a. l5

' Example 2 Percent Glycerine Qulnolirie 40 The latter composition israpidly absorbed by the cellulosic packing,'whereas, when glycerinealone is used the rate oi absorption is rather slow.

It is to be noted that in the case of high viscosity liquids such asglycerine, my tar penetrat-' ing agents also serve to reduce theviscosity thus reducing the time required for the composition to flowthrough the main when applied in this manner.

The foregoing are examples of liquid mixtures suitable for. generalleakage treatment. When deposits or coating or tar, resin and/0r gum areexcessive the following are more suitable in view ofthe increasedconcentration of the tar pene- Generally speaking, any other liquid orconibination of liquids of Table 1 may be substituted for diethyleneglycol or glycerine in the above examples. It is preferable to use amiscibility agent when necessary to form a single liquid phase, which isprefered to a plurality of liquid phases, although it is conceivablethat the latter may be employed without departing from the broad conceptof the invention.

Examples of liquid mixtures suited more particularly for dust layingonly are as follows:

Example 6 Percent Qui nnline 20 Mono phenyl ether of ethylene glycol 50Dicthylene glycoL. v 36 Ezamflle 7 Percent Quinnline Dibutyl phthalate'15 Mono-methyl ether of diethylene glycol..

Example 8 v Percent Dietliylene gly 50 Phenyl cellosolve Diglycol laur tl0 Qninnlinn 15 Mesityloxide Generally speaking, any other liquid orcombination of liquids of Table 4 may be substituted for the dust layingliquid or liquids in the above examples. It is preferable to use amiscibility agent when necessary to form a single liquid phase.

which is preferred to a plurality of liquid phases,

although it is conceivable that the latter may be employed withoutdeparting from the broad concept of the invention.

The treating liquid may be applied to the interior surface of a pipesection-and/or to the packing in a joint before, during or after theassembly of the pipe sections to form the main. This may be accomplishedin any desired manher such as by dipping, spraying, brushing, or

7 otherwise.

V or, in other words, so that the liquid is deposited If the main isalready in service, sections of I the main may be blocked oil" by meansof inflated bags or other means, and the sections then completely filledwith the liquid after which the liquid can be drawn oil and re-used.

On'the other hand, the liquid may be sprayed into the gas by the foggingprocedure earlier mentioned so that the packing and/or dust sourcesabsorb the liquid from the gas stream from the gas stream onto thepacking and/or onto the sources of dust.

In another method of application the liquid I is'introduced into themain at high points and allowed to run by gravity to low points wherethe excess can be drawn oil; An examination of l mains treated in thismanner shows that my compositions have greatly improved climbingproperties.

Another method comprises inserting a long length of hose into the mainwith a spray at its end, or with a plurality of sprays distributed alongits length, and pumping the treating liquid into the hose whilewithdrawing the hose either continuously or intermittently or otherwise,or

while the hose remains stationary.

In the last three methods of application service on the line need not beinterrupted. The packing becomes impregnated with the composition anddust sources become coated with the treating liquid. The wetting qualityof the treating liquid causes it to spread, climb and wet every exposedsurface. divided material causes it to be bound together in a mass whichprevents it from rising in a dust due to the gas traveling through themain. The

. clogging of mains, meters, regulators and appliance is thusefiectively prevented.

A typical gas main is illustrated in the drawing in which:

Figure 1 is a side elevation, partly in section, illustrating a gasmain; and

Fllgure 2 is a cross-section on line 2-2 of Figure In the drawing thegas main ll is shown with a joint comprising bell H and spigot l2fitting The wetting of finely deposits accumulated thereon.

within said bell and spaced therefrom. In the space betweenthe bell andthe spigot is cellulosic fiber packing l3 and a seal ll of lead or othersuitable material for holding the packing in place. The treating liquidI as illustrated is being run through the main by gravity. It contactsthe bottom of the main and any It also contacts the packing at space isleft between the spigot and the shoulder of the bell to provide forexpansion and contraction due to temperature changes. The packingabsorbs the liquid at 16 and the liquid climbs and is carried up in thepacking as shown, by the outer group of arrows in Figure 2. If asubstance of Table 1 is present the packing is swollen to substantiallythe same extent as with water. The treating liquid also climbs up themetal walls of main as illustrated by the in nor group of arrows inFigure 2 to coat dust sources in addition to those along the bottom oithe main.

The bulk of the treating liquid, of course, remains in the main onlyduring the time that its flow from the point of introduction to thegoint of removal which usually is the nearest Any other means forapplying the treating liquid to the packing and/or to the interior ofthe conduit may be employed. For instance, in the case of very largediameter mains the level of the liquid l5 may be raised or may be madeto fill the entire main if desired, or the spray or fogging methods maybe employed.

In the case of a welded main, or other main having joints in whichcellulosic fiber packing 18 which space gas distribution system whichcomprises applying to the interior of said system a liquid mix-. turecomprising at least one of a group consisting of ethylene glycol,diethylene glycol, monomethyl ether of ethylene glycol, monomethyl etherof diethylene glycol, and glycerine and at least one of a groupconsisting of quinoline and isoquinoline.

3. A method for treating fibrous packing such as jute and hemp in ajoint of a gas distribution system to reduce gas leakage therethrough,

is not present, the treatment becomes primarily I one of dust laying.Likewise, when the liquids of Table 4 other than those listed in Table 8are employed the treatment becomes more essentially one of dust layingregardless of the type of main treated.

While the invention has been described in connection with gas main it isto be understood that it is applicable to any part of a gas distributionsystem. wherein similar problems mav arise. It is also to be understoodthat the various agents referred to herein may be used either in thepure or commercially pure form, or in any other suitable form includingthe commercial and crude iorms.

It is to be understoodthat the above particular description is by way ofillustration and that changes, omissions. additions. substitutions,and/or modifications, might be made within the scope of the claimswithout departing from the spirit of the invention,

The terms "comprlsing and comprises are used in the claims in theirusually accepted meanings which donut exclude other steps or thepresence of substances other than those ape ciflcally recited. l

I claim: I i l. A method for treating the interior of a gas distributionsystem which comprises applying to the interior of said system a liquidmixture comprising a non-cyclic high boiling aliphatic alcohol andone-of a group consisting of quinollne and isoquinoline.

comprising impregnating said packing with a cellulosic fiber swellingagent selected from a group consisting of ethylene glycol, diethyleneglycol, monomethyl ether of ethylene glycol, monomethyl ether ofdiethylene glycol, and glycerine by bringing said agent into contactwith said packing in the presence of one of a group consisting ofquinciine and isoquinoline.

i. A method for laying dust in the interior of a gas distribution systemhaving dust sources, comprising enveloping said dust sources with. adust laying liquid selected. from a group consist ing of ethyleneglycol, diethylene glycol, monomethyl ether of ethylene glycol,mcnomethyl ether of diethylene glycol, and glycerine by bringing saidliquid into contact with said dust sources in the presence crude coaltar quinoline.

5. A method for rejuvenating cellulosic packing such as jute and hemp ina joint of a gas distribution system to reduce gas leakage at saidjoint, said packing being at least partially coated with deposits fromgas flowing through said system, which comprises contacting said packingwith a liquid mixture comprising crude coal tar quinoline and at leastone of a group consisting of ethylene glycol, diethylene glycol,monomethyl ether of ethylene glycol, mcnomethyl ether of diethyleneglycol, and glycerine.

6. A joint in a gas distribution system comprising spaced cooperatlngelements, cellulosic fibrous packing such as jute between said co- 2. Amethod for treating the interior oi a operating elements positioned toform a seal, and a liquid mixture absorbed by said packing, said liquidmixture comprising at least one of a group consisting of ethyleneglycol, diethylene glycol, mcnomethyl ether of ethylene glycol,

mcnomethyl ether of diethylene glycol, and

glycerine and at least one of a group consisting of quinoline andisoquinoline.

7. A joint in a gas distribution system comprising a bell, a spigotpositioned within and spaced from said bell-to form an annular space, anannular ring of cellulosic fibrous packing in said annular space andcontinuouslycontacting said bell and spigot on its outer and inner p8?ripheries respectively, and a liquid mixture absorbed by said packing,said liquid mixture comprising at least one of a group consisting ofethylene glycol, diethylene glycol, monomethyi ether of ethylene glycol,mcnomethyl ether of diethylene glycol, and glycerine and at least one ofa group consisting of quinoline and isoquinoline.

8. A gas conduit having interior dust sources wetted down with a liquidmixture comprising a non-cyclic. high boiling aliphatic alcohol, and atleast one of a group consisting of quinoline and isoquinoline.

JOHN R. SKEEN.

